Mekong Dolphins on the Brink of Extinction

Pollution in the Mekong River has pushed the local population of Irrawaddy dolphins to the brink of extinction, a new report by WWF has revealed. [Download the full report: PDF, 805KB]

The Mekong River Irrawaddy dolphin (Orcaella brevirostris) population inhabits an approximately 100-mile portion of the Mekong River between Cambodia and Laos. Since 2003, the population has suffered 88 deaths – of which over 60 percent were calves under two weeks old. The latest population is estimated between 64 and 76 members.

Researchers found toxic levels of pesticides such as DDT and environmental contaminants such as PCBs during analysis of the dead dolphin calves. These pollutants may also pose a health risk to human populations living along the Mekong that consume the same fish and water as the dolphins.

High levels of mercury were also found in some of the dead dolphins. Mercury, suspected to be from gold mining activities, directly affects the immune system making the animals more susceptible to infectious disease.

Limited genetic diversity due to inbreeding was another factor in the dolphin deaths, as the Mekong River dolphins are isolated from other members of their species. Science has shown that protecting cetaceans’ habitat is a successful conservation strategy for species recovery.

What is WWF doing?WWF, through our offices in Cambodia, is working closely with the government to develop a dolphin recovery plan. The WWF Greater Mekong office is also supporting a trans-boundary dolphin management project between Cambodia and Laos. Key elements of the work are:

joint regulation for managing the trans-boundary conservation area for the dolphin

establishment of inventory of trans-boundary aquatic resource

raising public awareness

promoting responsible tourism

continued Irrawaddy dolphin research

Species spotlight:The Mekong River Irrawaddy dolphin is regarded as a sacred animal by both the Khmer and Lao people, and is an important source of income and jobs for communities involved in dolphin-watching ecotourism initiatives.More on the Mekong River Irrawady doplphin

WWF works here:The Greater Mekong Region’s wide range of habitats support extraordinary levels of biodiversity. Well-known species such as the Indo-Chinese tiger, Irrawaddy dolphin and Javan rhino live here, as well as newly-discovered fauna.

More than 60 million people in the lower Mekong basin depend on the river system for food, transport and economic activity.

The Mekong River produces an estimated 2.5 million tons of fish per year, with a value of at least $2 billion, making it the largest inland fisheries in the world.

Eighty percent of the animal protein for Mekong inhabitants comes from the Mekong, with 70 percent of the commercial catch being long distance migrant species. More on the Mekong.